This invention is directed to a control system for the manufacture of a product. The control system of this invention has the capability of rapid information processing and decision-making, minimizing production cycle time, efficiently allocating resources, and minimizing excess costs.
In the production of products, the work effort is a sequence of activities. The proper control of these activities is as important to the efficient transformation of the product from its initial state into its finished state as are the individual activities themselves. Just as an improvement in each activity can improve the production rate, an improvement in the control of the production process can produce a similar reduction in total cost and the elapsed time of production. In the production of any product, the costs of idle waiting time, penalties of late deliveries, unjustified expediting costs, and the costs of excess inventories must be minimized.
One system that has addressed this problem is the Critical Path Method(CPM), in which a network of activities is created that represents the sequence of activities and the interdependencies of the activities in the particular production process. A variation on this basic method is Project Evaluation and Review Technique (PERT) which uses multiple estimates of time durations to provide a probabilistic estimate. These systems are available as computer software. To use these systems, the networks are analyzed to find the critical path, i.e., the path that is, in effect, the longest duration, and which determines the final completion date.
A major inherent problem of these systems is that new information must be evaluated by serial searching; each new bit of information must be entered and the computer program run to determine the effect on the completion date. Further, to evaluate the effect of several potential changes, all combinations of the changes must be entered and individually run. This is a considerable expense in time and money on a large project. Also, near critical items which may become critical if they experience a slight delay, are not identified. Further, all the information must be entered into one large computer program thereby requiring centralized processing and decision making. Although valuable, these systems do not provide an easy and timely visibility into the critical items and their degree of impact. Also, these systems do not offer a means to balance resources in order to minimize the time and cost of a project. These systems do not support Enterprise-Wide Project Management(EWPM) because the centralized decision making makes them intractable and they offer no methodology for optimization.
U.S. Pat. Nos. 4,648,023 and 5,291,397 describe a new method of centralized analysis and control using a central computer. U.S. Pat. Nos. 4,648,023 and 5,291,397 are incorporated by reference. This method described in these patents does not incorporate the advantage of decentralizing the analysis and decision-making to the local level to empower the local manager. Since the local manager is the expert in utilizing his resources, it would be advantageous to provide him with the tools and information to optimize the use of these resources.